Many suspended ceiling systems have been proposed and are used extensively in building construction to improve the overall appearance of the office space, to allow access to the area above the ceiling where mechanical equipment and piping is often located, and to improve the acoustics of the space. Systems of this general type would include U.S. Pat. No. 2,101,349, U.S. Pat. No. 2,065,796, U.S. Pat. No. 3,430,338, U.S. Pat. No. 4,004,390, U.S. Pat. No. 4,027,446, U.S. Pat. No. 2,616,197, U.S. Pat. No. 3,279,139, U.S. Pat. No. 3,513,613, U.S. Pat. No. 4,019,300, Canadian Pat. No. 696,145 and Canadian Pat. No. 697,832. A suspended ceiling system is also disclosed in our pending Canadian Application Ser. No. 379,053 which corresponds to U.S. patent application Ser. No. 277,166 which are both assigned to the Applicant of the present application.
The problem with the prior art structures is that the main thrust, generally speaking, has been to provide a fairly simple inexpensive suspended ceiling system for use in a variety of applications, however, these systems although inexpensive are certainly not as attractive as a plastered ceiling. The earlier patents generally use what is referred to as a non-concealed system in that the individual grid members used to support the ceiling panels are exposed to the lower surface and as such are visible. More recently concealed ceiling panel systems have been proposed wherein the panels cover the individual grid support network and this is accomplished by having adjacent panels abut in one fashion or another. Generally, concealed ceiling systems are more expensive and therefore the quality of the system is superior. Several major problems occur with concealed ceiling systems, such as:
1. alignment of the edges of the panels to provide straight lines in both the length and width of the ceiling system;
2. control of the level of the individual panels beneath the grid work within a fairly narrow range as variation in the height of the panels is easily recognized from beneath due to light variations; and
3. an adequate air seal between the support grid and the ceiling panels.
The present invention is designed to alleviate the above problems of concealed suspended ceiling systems.